Siloxacyclopentenes as dienophile-linked directing groups in intramolecular Diels-Alder reactions.
The synthesis and intramolecular Diels-Alder reactions of trienes 5 and 6 with a siloxacyclopentene-constrained dienophile are described. These reactions provide the primary cycloadducts 7 and 8 with high diastereoselectivity. These cycloadducts possess trans-relationships between the ring fusion proton and the adjacent C(1) alkoxy group and can be further elaborated to alcohols 9 and 11 (via protiodesilylation) or to 10 and 12 (via Fleming-Tamao oxidation) depending on the substitutent R.
Halvorsen
Geoff T
GT
Department of Chemistry, Scripps-Florida, Jupiter, Florida 33458, USA.
Roush
William R
WR
D000080:Acetals / Q000737:chemistry; D003517:Cyclopentanes / Q000737:chemistry*; D019855:Ethylene Glycol / Q000737:chemistry; D011090:Polyenes / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry*; D013237:Stereoisomerism
D000080:Acetals; D003517:Cyclopentanes; D011090:Polyenes; D012833:Siloxanes; C521219:siloxacyclopentene; D019855:Ethylene Glycol